Search results for " Automata"
showing 10 items of 436 documents
Quantum Real - Time Turing Machine
2001
The principles of quantum computation differ from the principles of classical computation very much. Quantum analogues to the basic constructions of the classical computation theory, such as Turing machine or finite 1-way and 2-ways automata, do not generalize deterministic ones. Their capabilities are incomparable. The aim of this paper is to introduce a quantum counterpart for real - time Turing machine. The recognition of a special kind of language, that can't be recognized by a deterministic real - time Turing machine, is shown.
Automata and forbidden words
1998
Abstract Let L ( M ) be the (factorial) language avoiding a given anti-factorial language M . We design an automaton accepting L ( M ) and built from the language M . The construction is effective if M is finite. If M is the set of minimal forbidden words of a single word ν, the automaton turns out to be the factor automaton of ν (the minimal automaton accepting the set of factors of ν). We also give an algorithm that builds the trie of M from the factor automaton of a single word. It yields a nontrivial upper bound on the number of minimal forbidden words of a word.
Finite Automata with Advice Tapes
2013
We define a model of advised computation by finite automata where the advice is provided on a separate tape. We consider several variants of the model where the advice is deterministic or randomized, the input tape head is allowed real-time, one-way, or two-way access, and the automaton is classical or quantum. We prove several separation results among these variants, and establish the relationships between this model and the previously studied ways of providing advice to finite automata.
Minimal forbidden words and factor automata
1998
International audience; Let L(M) be the (factorial) language avoiding a given antifactorial language M. We design an automaton accepting L(M) and built from the language M. The construction is eff ective if M is finite. If M is the set of minimal forbidden words of a single word v, the automaton turns out to be the factor automaton of v (the minimal automaton accepting the set of factors of v). We also give an algorithm that builds the trie of M from the factor automaton of a single word. It yields a non-trivial upper bound on the number of minimal forbidden words of a word.
Digital calculus: Cellular automata dynamics in closed form
2015
A simple mathematical expression for the universal map for cellular automata is found in closed form with the help of a digit function, whose most basic properties are established. This result is found after proving a theorem on the composition of functions on finite sets. The expression (and the technique used to obtain it) opens the possibility of gaining mathematical insight in any cellular automaton rule since it constitutes at the same time a simple and fast algorithm to implement any such rule.
Query automata
1999
A main task in document transformation and information retrieval is locating subtrees satisfying some pattern. Therefore, unary queries, i.e., queries that map a tree to a set of its nodes, play an important role in the context of structured document databases. We want to understand how the natural and well-studied computation model of tree automata can be used to compute such queries. We define a query automaton (QA) as a deterministic two-way finite automaton over trees that has the ability to select nodes depending on the state and the label at those nodes. We study QAs over ranked as well as over unranked trees. Unranked trees differ from ranked ones in that there is no bound on the num…
Negative results in the theory of games with lexicographic utilities
2003
When players may have lexicographic utilities, there are: (i) extensive games having a non-empty set of equilibria but empty sets of sequentially rational, sequential and perfect equilibria (ii) normal form games having a non-empty set of equilibria but an empty set of proper equilibria and no stable set of equilibria and (iii) two extensive games having the same normal form representation and disjoint sets of sequential equilibria.
Some decisional problems on rational relations
1997
Abstract In this paper we prove that the problem of deciding whether a deterministic rational relation is star-free is recursively solvable, although the same problem for any rational relation is undecidable. We also prove that a rational relation is star-free if and only if it is aperiodic and deterministic.
Bounded Computational Capacity Equilibrium
2010
We study repeated games played by players with bounded computational power, where, in contrast to Abreu and Rubisntein (1988), the memory is costly. We prove a folk theorem: the limit set of equilibrium payoffs in mixed strategies, as the cost of memory goes to 0, includes the set of feasible and individually rational payoffs. This result stands in sharp contrast to Abreu and Rubisntein (1988), who proved that when memory is free, the set of equilibrium payoffs in repeated games played by players with bounded computational power is a strict subset of the set of feasible and individually rational payoffs. Our result emphasizes the role of memory cost and of mixing when players have bounded c…
Learning Automaton Based On-Line Discovery and Tracking of Spatio-temporal Event Patterns
2010
Published version of an article from the book: Lecture Notes in Computer Science, 2010, Volume 6230/2010, 327-338. The original publication is available at Springerlink. http://dx.doi.org/10.1007/978-3-642-15246-7_31 Discovering and tracking of spatio-temporal patterns in noisy sequences of events is a difficult task that has become increasingly pertinent due to recent advances in ubiquitous computing, such as community-based social networking applications. The core activities for applications of this class include the sharing and notification of events, and the importance and usefulness of these functionalites increases as event-sharing expands into larger areas of one’s life. Ironically, …